1. Technical Field
The present invention relates to cooling technologies, and more particularly, to a cooling plate for cooling articles in a board-like shape.
2. Description of Related Art
An existing photovoltaic device typically has a glass substrate deposited thereon a Mo layer, in which a light absorption layer (e.g. a CIGS layer or a CIS layer) is formed. In the course of forming the light absorption layer, the assembly has to be first heated to a temperature higher than 500° C. before sputtering, evaporation, electroplating or ink-jet is conducted to deposit the light-absorbing material on the Mo layer.
After the light absorption layer is made as described previously, the resulting photovoltaic device needs to be cooled for subsequent or additional processing. Since the glass substrate in the photovoltaic device tends to deform or break when the temperature difference between its upper and lower surfaces is greater than 150° C. or when the temperature difference between different regions in the same surface is greater than 25° C., the cooling cannot be performed naturally in the ambient temperature but requires a specially designed cooling means that is able to cool the glass substrate promptly and evenly, thereby facilitating subsequent or additional processing.
A known cooling means for such purpose is a cooling plate that delivers cool gas to the glass substrate. As depicted in FIG. 11, a conventional cooling plate 80 has its one side communicated to a gas source 99 that supplies a cooling gas, and distributes the gas to air outlets 821 formed on its lower board 82, so as to cool the glass substrate placed therebeneath. However, since the gas source 99 is provided unilaterally, the air outlets 821 near the gas source 99 present greater gas output due to the higher gas pressure as compared to those farther from the gas source 99. This renders the entire cooling plate 80 having an uneven distribution of gas output, which in turn, causes uneven cooling of the glass substrate. Such uneven cooling may then lead to temperature difference between different regions in the same surface in excess of 25° C. that is responsible for breaking or deformation of the glass substrate. Therefore, the prior art needs to be improved.